how to set communication between ac800m controller ans s7-300 controller
Voted best answer
For a Siemens S5 or S7 the best interface is usually a profibus link. The link is fast, easy to set up and can transfer large amounts of data. Since the S7 appears just like any other profibus IO module there is very little programming required in the AC800. The AC800 will be the master and the S7 is a slave.
You need a profibus slave module in the S7. This link should help you configure the siemens side http://support.automation.siemens.com...
On the AC800M side, import the GSD file to create a hardware definition, add the hardware modules and configure the I/ O variables To match the S7.
I will suggest you to use DP-DP coupler module. This module establishes communication between any two masters(say ABB and Siemens). You will find the configuration in web(search for DP-DP coupler). Using this you can establish profibus communication between Siemens and ABB. Then from ABB, you can configure it as a profibus node.
Hope this helps..